Known inlet devices, such as for example the one described in FR 2 771 796, comprise a male inlet end-piece, inside a bowl formed by a protective peripheral skirt. This inlet end-piece is intended to collaborate with an ejection valve of the canister to move the valve element away from its seat and thus allow gas to be transferred from the canister into the inlet device of the appliance. During the transfer operation, it is necessary to make a seal around the valve of the canister and the inlet end-piece of the appliance. For this purpose, the ejection valve of the canister is often, and particularly in the case of the canister described in FR 2 771 796, extended in the form of a male end-piece which collaborates with the inlet male end-piece of the appliance inside an appropriately designed connector.
Such an arrangement does, however, have the disadvantage that the end-piece of the ejection valve of the canister protrudes from the edge of a protective cup, with the risk of it being broken off while it is being handled, not to mention the problems associated with storage.